A group from the University of Tokyo and other organizations has announced the results of an experiment showing that the BA.8 strain of the Omicron variant, which was the mainstream in the eighth wave of the spread of the new coronavirus, is difficult to grow in a state of high fever. It may lead to the elucidation of the reason why the percentage of people who become seriously ill with the Omicron variant was low.
This research was published in the international scientific journal The Lancet Microbe by a group led by Project Professor Yoshihiro Kawaoka of the Institute of Medical Science, the University of Tokyo, and Professor Takeshi Noda of Kyoto University.
The group created lung cells from human iPS cells and infected them with the Delta and Omicron variants BA.5 and BQ.1.1, and compared the increase in the number of viruses.
As a result, at 37 degrees Celsius, which is close to normal, the number of mutated viruses increased 2,10 to 100 million times after two days.
On the other hand, at 40 degrees, the Delta variant increased as it did at 37 degrees, but the increase in BA.5 was only 1000,1 times, and the increase in BQ.1.<> was not.
According to the group, the Omicron variant is difficult to grow with high fever, and may be related to the fact that the proportion of people who become seriously ill is lower than when infected with the Delta variant.
Project Professor Kawaoka says, "The fact that it does not increase in an environment of 40 degrees Celsius is similar to seasonal influenza, and the nature of the new coronavirus may have changed over the past three years."